Gaza City residents were seen collecting water from a water truck on Saturday, a day after the world's leading authority on food crises said the Gaza Strip's largest city was gripped by famine.

The Integrated Food Security Phase Classification, or IPC, said famine is happening in Gaza City, home to hundreds of thousands of Palestinians, and could spread south to Deir al-Balah and Khan Younis by the end of next month.

The determination comes after months of warnings by aid groups that Israel's restrictions of food and other aid into Gaza, and its military offensive, were causing starvation among Palestinian civilians, particularly children.

Israel rejected the report, with Prime Minister Benjamin Netanyahu calling it an “outright lie.”

The grim milestone — the first time the IPC has confirmed a famine in the Middle East — is sure to ramp up international pressure on Israel, which has been fighting Hamas since the militant group's Oct. 7, 2023, attack. Israel says it plans to seize Gaza City and other Hamas strongholds, an escalation experts say will exacerbate the hunger crisis.

The IPC said hunger has been driven by fighting and the blockade of aid, and magnified by widespread displacement and the collapse of food production in Gaza, pushing hunger to life-threatening levels across the entire territory after 22 months of war.

More than half a million people in Gaza, about a quarter of its population, face catastrophic levels of hunger, with many at risk of death from malnutrition-related causes, the IPC report said.

U.N. Secretary-General António Guterres said the findings show a “human-made disaster, a moral indictment, and a failure of humanity itself” and appealed for an “immediate ceasefire.”

Netanyahu denies there's hunger in Gaza, calling reports of starvation “lies” promoted by Hamas. “The IPC report is an outright lie. Israel does not have a policy of starvation,” his office posted on X.

The U.S. State Department also sought to cast doubt on the report. It said the humanitarian situation in Gaza “is a serious concern,” but blamed Hamas and looters for the difficulties in delivering aid.

Formal famine determinations are rare. The IPC says a famine exists in an area when all three of the following conditions are confirmed: